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Food Science Terms
Ch. 22-Mixtures: Solutions, Colloidal Dispersions, and Suspensions
Question | Answer |
---|---|
dispersed phase | refers to particles that are scattered throughout a medium |
continuous phase | the medium in which particles are distributed |
vapor pressure | pressure at which gases escape from and dissolve into a liquid at the same rate. |
mass percent | is the percentage of the mass in a solutuion that comes from the solute |
colloidal dispersion | are mixtures in which microscopic particles of one substance are evenly distributed in another substance. Ex. jelly, mayonnaise,butter and gelatin |
colloid | are macromolecules or clumps of smaller molecules. |
Tyndall effect | when light is passed through a colloidal dispersion, the light rays scatter and are visible. |
homogenization | mechanical process that alters the chemical nature of fat particles, keeping them from re-collecting and rising to the top. |
emulsion | a mixture of two immiscible liquids, where one is dispersed in droplet form in the other. |
immiscible liquids | are liquids that will separate when combined. Usually one is polar in nature, like water-based vinegar and the other is nonpolar, like oil. |
temporary emulsions | are unstable mixtures of two immiscible liquids - as the mixture stands, the liquids will separate. |
emulsifier | molecule that has a polar end & a nonpolar end. Polar end attracted to, hydrogen bonds with polar molecules. Nonpolar end attracted to nonpolar molecules. Most emulsifiers require agitation, stirring, or beating for emulsifier to stablilize mixture. |
thermal conductivity | the ability to transfer heat energy |
foam | colloidal dispersions of gas or air bubbles dispersed in a liquid. Unstable foam - froth on top of root; meringue example of stable foam |
suspension | is a mixture of undissolved particles in a liquid. |
solubility | describes the amount of solute that will dissolve in a solvent. Factors affecting include temperature, particle size, concentration of a solution, agitation, vapor pressure |